Wave energy converter power take-off with active oil-hydraulic accumulator

Gaspar, J.F.; Zeng, C.; Xu, H.T.; Hallak, T.S.; Soares, C. Guedes; Mendes, M.J.G.C.

Key information

Authors:

Gaspar, J.F. (José Manuel Ferreira Gaspar); Zeng, C.; Xu, H.T. (Haitong Xu); Hallak, T.S. (Thiago Saksanian Hallak); Soares, C. Guedes (Carlos Guedes Soares); Mendes, M.J.G.C.

Published in

2024

Abstract

A new concept of an oil-hydraulic accumulator is proposed in this work to improve the harvesting performance of wave energy converters. The oil-hydraulic power take-off converts the reciprocating motion of the wave energy converter prime mover into the rotation of the generator shaft. Oil-hydraulic power take-offs integrated with accumulators are commonly classified as constant-pressure type. Conventional accumulators reduce the pressure fluctuation in the hydraulic systems but also impose limitations on the adaptability of the power take-offs to different sea states. This accumulator consists of two standard accumulators whose gas chambers are interconnected so that the charging characteristics of the accumulator can be adjusted by compressing or decompressing the gas in the shared chambers. Thus, compared to the conventional power take-offs, the power take-off integrated with the active accumulator system can be actively adapted to different sea states and ultimately improve the harvesting performance of the wave energy converter. The work focuses on the numerical implementation of the concept and the results indicate the accumulator concept brings significant advantages compared to the conventional in terms of better power output over a wide range of sea states.